bug use open_grpc_stream create health stream and send failed grpc server panic

[pi-pi-miao]

use grpc stream code potential risks panic

example:
match self.open_grpc_stream(
request.get_redis_addr(),
"package.name",
"MetricStream",
vec![],
) {
Err(e) => {
error!("open grpc err {:?}",e);
false
}
Ok(status) => {
// grpc server is health
// sudden the grpc server is crash or other thing
self.send_grpc_stream_message(status, Some(&msg), true); // here will panic ,because grpc server is crash
true
}
}